Ghouls

Ghouls have been touched upon lightly and infrequently in the Discworld series. They may or may not be a type of undead species, they certainly have a taste for human flesh, and they have integrated into human society to some degree. A minor but possibly important fact is that ghouls make quite good chefs. The only named member of the species so far is Mrs. Drull from the Fresh Start Club in Reaper Man, who we are told these days does children's party catering.